1. Technical Field
The present invention relates to a high-precision semiconductor device probing apparatus, and more particularly, to a vertical probing apparatus with an alignment mechanism which improves the precision of the vertical semiconductor device probing.
2. Background
In semiconductor testing process, a conductivity test is sometimes performed to detect defective products before dicing by bringing conductive probes into contact with testing pads on a semiconductor wafer. When the conductivity test is performed, in order to send a signal to the testing device or to transfer a signal generated by the test, a probing apparatus or a probe card including a large number of probes is used. During the test, a number of probes are brought into contact with a number of dies on the semiconductor wafer while the dies are scanned by the probe card. However, because several hundred to several thousand dies are formed on the semiconductor wafer, considerable time is required to test a single semiconductor wafer.
The vertical probe offers the vertical displacement required by the probe tip to contact the integrated circuit device under test using the deformation of the probe body itself, and can be arranged in a very fine pitch manner. However, an issue arising from the vertical probe is the difficulty in alignment between the probe tip and the testing pads of the integrated circuit. The arrangement of the vertical probes is designed to perform the fine-pitch testing at the expense of precise alignment. Misalignment not only generates inaccurate signals but also damages the semiconductor die if excess pressure is exerted on the testing pad or, even worse, on the die itself.
FIG. 1 illustrates a conventional probing apparatus 10 for testing semiconductor devices. A probe head 11 comprising a plurality of vertical pins is configured to establish electrical connection between a semiconductor device wafer 13 to be tested and a circuit board 12. Each vertical probe has a tip end 15 for contacting a testing pad on the semiconductor device wafer 13, and a connector end 14 for contacting the circuit board 12. The circuit board 12 acts as an interface to transfer a signal to and from the semiconductor device wafer 13. As shown in FIG. 1, the probe head 11 shadows all the vertical pins carried within, rendering the alignment between the tip end 15 of the vertical pins and the corresponding testing pads on the semiconductor device wafer 13 difficult, assuming the alignment is carried out from the top of the conventional probing apparatus, such as using an optical microscope observing thorough an open structure.
Because the density of modern integrated circuits continues to increase consistently, a probing apparatus equipped with a fine-pitch testing structure but with a mechanism contributing to high precision alignment is crucial in today's semiconductor testing technology.